Satellite radar tracking sees off toothfish pirates

Actual pirates, in boats, with earrings

The endangered Patagonian toothfish is getting a helping hand from Envisat, one of Europe's research satellites. According to the European Space Agency (ESA), a radar monitoring scheme using data from Envisat and Radarsat-1 has reduced the illegal fishing in one region by around 90 per cent.

Envisat is a polar-orbiting Earth observation satellite, launched to gather data on the atmosphere, ocean, land, and ice. Now, it is also being use to keep track of fishing vessels in the vicinity of the endangered fish, helping to keep it safe from pirate vessels.

The Patagonian toothfish, also known as Chilean seabass, was discovered 25 years ago by Antarctic researchers. Since then it has been fished almost to extinction. This is partly because it is such a long-lived fish, and takes around 10 years to mature sexually, so any over fishing has a huge impact on the population.

Restrictions have been placed on how much can be fished, but according to the BBC, some 100,000 tonnes are still taken from the sea illegally every year. ESA puts this figure at around 26,000.

Legal quotas total around 10,500 tonnes annually. But with the fish fetching as much as $1,000 each (according to the NYT), the motive for piracy is quite clear.

The project is part of France's attempt to limit illegal fishing in its territories off the coast of Réunion Island. Patagonian toothfish earns Réunion Island between €40m and €60m each year, an income the region can ill-afford to lose to piracy.

France maintains an economic exclusion zone around Réunion Island, in which only French ships are allowed to fish, but the area is too large to be effectively policed from the sea.

Legal boats should all carry an Argos satellite transmitter, which allows them to identify themselves, and also shows their location. Envisat tracks all vessel activity in the area and this data is cross referenced with the Argos data to rule out legitimate vessels.

Any other vessels in the area can be investigated further by French marine patrols. Indeed, shortly after the system went live in 2004, French authorities intercepted a vessel, the Apache, carrying 60 tonnes of illegally fished Patagonian toothfish.

Philippe Schwab, technical director of CLS, a subsidiary of the French space agency CNES, said that the system seemed to be working well as a deterrent. He commented: "Today, illegal fishing [in this region] has almost disappeared. It seems that the unscrupulous fishermen have understood the efficiency of the system."

It is not clear whether there has been an overall reduction in piracy or whether the illegal fishing has merely moved to a less watched region. ®